Certain products are packaged in containers closed by a stopper, which sometimes tops a membrane seal. The presence of a membrane seal improves the storage duration of the product and indirectly certifies the authenticity of the contents to the consumer. Based on needs, membrane seals are made from flexible materials, and are sometimes formed by a stack of several layers secured to one another. Furthermore, the use of membrane seals in the context of authenticating contents implies that they are generally made from fragile materials, such that they must be irreparably damaged to access the product.
Some fraudulent operators, however, have used very fine syringes to siphon and replace the contents of certain containers without damaging the membrane seals. Membrane seals that do not protect against this type of manipulation are not fulfilling their role regarding the authentication of contents.